windows: simplify a bit (#493)

The sys* constants were used in the old golang.org/x/exp/winfsnotify
package on which this is based, but haven't been in use for a long time.

Remove the "one shot", "dir only", and "ignore" options as they were
never set. Also don't send "sysFSQOVERFLOW" as an event if the buffer is
too long; we already send an error and it's just a weird magical number
you get.

This could be simplified greatly more by removing the whole
sysFS… → windows.FILE_NOTIFY… → sysFS… conversions, but that's for
another day.

diff --git a/windows.go b/windows.go
index 17ada311debb6fc702fbdc67b152951c9794547f..9b43d386a413259338f6ed4ca57ac17f47be12b9 100644 (file)
--- a/windows.go
+++ b/windows.go
@@ -151,16 +151,11 @@ func (w *Watcher) WatchList() []string {
 // add various options to the watch. This has long since been removed.
 //
 // The "sys" in the name is misleading as they're not part of any "system".
+//
+// This should all be removed at some point, and just use windows.FILE_NOTIFY_*
 const (
-       // Options for AddWatch
-       sysFSONESHOT = 0x80000000
-       sysFSONLYDIR = 0x1000000
-
-       // Events
-       sysFSACCESS     = 0x1
        sysFSALLEVENTS  = 0xfff
        sysFSATTRIB     = 0x4
-       sysFSCLOSE      = 0x18
        sysFSCREATE     = 0x100
        sysFSDELETE     = 0x200
        sysFSDELETESELF = 0x400
@@ -169,10 +164,7 @@ const (
        sysFSMOVEDFROM  = 0x40
        sysFSMOVEDTO    = 0x80
        sysFSMOVESELF   = 0x800
-
-       // Special events
-       sysFSIGNORED   = 0x8000
-       sysFSQOVERFLOW = 0x4000
+       sysFSIGNORED    = 0x8000
 )
 
 func (w *Watcher) newEvent(name string, mask uint32) Event {
@@ -302,9 +294,6 @@ func (w *Watcher) addWatch(pathname string, flags uint64) error {
        if err != nil {
                return err
        }
-       if flags&sysFSONLYDIR != 0 && pathname != dir {
-               return nil
-       }
 
        ino, err := w.getIno(dir)
        if err != nil {
@@ -427,11 +416,7 @@ func (w *Watcher) startRead(watch *watch) error {
                err := os.NewSyscallError("ReadDirectoryChanges", rdErr)
                if rdErr == windows.ERROR_ACCESS_DENIED && watch.mask&provisional == 0 {
                        // Watched directory was probably removed
-                       if w.sendEvent(watch.path, watch.mask&sysFSDELETESELF) {
-                               if watch.mask&sysFSONESHOT != 0 {
-                                       watch.mask = 0
-                               }
-                       }
+                       w.sendEvent(watch.path, watch.mask&sysFSDELETESELF)
                        err = nil
                }
                w.deleteWatch(watch)
@@ -522,7 +507,6 @@ func (w *Watcher) readEvents() {
                var offset uint32
                for {
                        if n == 0 {
-                               w.Events <- w.newEvent("", sysFSQOVERFLOW)
                                w.sendError(errors.New("short read in readEvents()"))
                                break
                        }
@@ -570,11 +554,7 @@ func (w *Watcher) readEvents() {
                        }
 
                        sendNameEvent := func() {
-                               if w.sendEvent(fullname, watch.names[name]&mask) {
-                                       if watch.names[name]&sysFSONESHOT != 0 {
-                                               delete(watch.names, name)
-                                       }
-                               }
+                               w.sendEvent(fullname, watch.names[name]&mask)
                        }
                        if raw.Action != windows.FILE_ACTION_RENAMED_NEW_NAME {
                                sendNameEvent()
@@ -583,11 +563,8 @@ func (w *Watcher) readEvents() {
                                w.sendEvent(fullname, watch.names[name]&sysFSIGNORED)
                                delete(watch.names, name)
                        }
-                       if w.sendEvent(fullname, watch.mask&w.toFSnotifyFlags(raw.Action)) {
-                               if watch.mask&sysFSONESHOT != 0 {
-                                       watch.mask = 0
-                               }
-                       }
+
+                       w.sendEvent(fullname, watch.mask&w.toFSnotifyFlags(raw.Action))
                        if raw.Action == windows.FILE_ACTION_RENAMED_NEW_NAME {
                                fullname = filepath.Join(watch.path, watch.rename)
                                sendNameEvent()
@@ -615,9 +592,6 @@ func (w *Watcher) readEvents() {
 
 func (w *Watcher) toWindowsFlags(mask uint64) uint32 {
        var m uint32
-       if mask&sysFSACCESS != 0 {
-               m |= windows.FILE_NOTIFY_CHANGE_LAST_ACCESS
-       }
        if mask&sysFSMODIFY != 0 {
                m |= windows.FILE_NOTIFY_CHANGE_LAST_WRITE
        }